This invention relates to a method and system for providing vehicle handling feedback to an operator of a motor vehicle.
With the advent of improved suspension systems, a driver of a motorized vehicle has become increasingly isolated from the feel of the road and the vehicle""s response to the road. Accordingly, a driver receives little feedback from the vehicle relating to its handling. For example, a driver taking a turn at an excessive speed may not feel the lateral roll of the vehicle. In addition, if the driver brakes excessively, he may not necessarily feel the vehicle slipping. The absence of feedback is undesirable, resulting in less than optimal vehicle control by the driver.
Systems do exist that provide the driver with some feedback relating to the undesired movement of the vehicle. ABS systems are currently equipped to provide feedback through a signal on the dashboard that may flash when the vehicle is slipping. However, a driver focusing on the road may miss or ignore this feedback.
A need therefore exists for a method and system of providing feedback to the driver relating to the undesired movement of the vehicle without requiring significant attention from the driver to notice.
The present invention provides feedback about the movement of a vehicle through the vehicle""s steering wheel. The steering system comprises a vehicle steering wheel and a feedback mechanism providing feedback through the steering wheel. A sensor obtains information about the movement of the vehicle and communicates this information to a control unit. The control unit controls the feedback mechanism based on the input from the sensor.
The feedback mechanism may cause tactile feedback in the steering wheel so that the driver may keep his eyes focused on the road while still receiving feedback through the steering wheel. The feedback preferably is applied as vibration of the steering wheel.
As commonly found on vehicles today, a power steering unit may assist steering of the vehicle. In this instance, the steering wheel may be vibrated by controlling a solenoid valve of the power steering unitxe2x80x94a valve common in such a unit. If the power steering unit does not employ a solenoid valve, one may be easily added. By pulsing the solenoid valve, hydraulic fluid to a hydraulic pump of the power steering unit may be interrupted. Each interruption causes the steering wheel to vibrate. Hence, with little additional componentry, the invention may be implemented into existing power steering systems.
The sensor of the invention detects movement of the vehicle, such as vehicle roll or vehicle slip. The sensor may already be part of an existing ABS brake system and tied to the control unit that controls the feedback mechanism. Additionally, an accelerometer may be used to provide information about the lateral roll forces experienced by the vehicle.
The level of feedback fed through the steering wheel may depend on the level of movement of the vehicle. In this way, a driver may be provided with increasing levels of feedback as the level of undesirable movement increases. For example, as vehicle slippage increases, the level of vibration of the steering wheel may also increase, thereby providing greater warning to the driver of the undesirable movement of the vehicle.
Accordingly, the invention senses movement of the vehicle and communicates this movement to a control unit. A driver receives feedback of the movement of the vehicle through the steering wheel based on the sensed movement. Thus, the invention provides feedback that the driver may otherwise fail to notice and does so without significant additional expense in the manufacture of the vehicle.